This application is based on and incorporates herein by reference Japanese Patent Application Nos. 2000-16075 filed Jan. 25, 2000 and 2000-315556 filed Oct. 16, 2000.
1. Field of the Invention
This invention relates to an electrical noise suppressing device for motors.
2. Related Art
Direct current electrical motors generate electrical noises due to sliding contact between brushes and commutators. The noise will influence electronic devices disposed around the motor. Electrical component parts such as choke coils and capacitors are provided in the motor, specifically between the brushes and power supply terminals which are connectable with an external electrical power source, to suppress generation of electrical noise. Motors are designed to have a structure for supporting the noise suppressing component parts therein so that those noise suppressing component parts may be mounted and supported thereby as the case may be. As a result, the supporting structure for the noise suppressing component parts requires more space in the motor, but may become useless in some motors which do not need such component parts.
It is therefore an object of the present invention to provide an electrical noise suppressing device for motors which requires less mounting space and less cost.
According to the present invention, an electrical noise suppressing device for a motor is constructed to be attachable to a motor which has a pair of motor-side connecting terminals connectable to a pair of source-side connecting terminals of an electrical power source. The noise suppressing device has a casing having a shape attachable to the motor at a side of the motor-side connecting terminals. A pair of connecting terminals are fixedly disposed in the casing and connectable with the motor-side connecting terminals and the source-side connecting terminals. Electrical noise suppressing components are disposed in the casing and connected to the connecting terminals of the casing for suppressing electrical noise generated in the motor. Preferably, the noise suppressing components have a longitudinal shape and is disposed in such a manner that its longitudinal direction is perpendicular to a direction in which the connecting terminals of the casing face each other.